2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Shot from the movie "Gemini"
Polish scientists have shown that blind people can determine the relative height of a person only by the sound of his voice. The researchers asked the blind to listen to paired recordings of vowel sounds pronounced by men of different heights and determine which of the two men is taller by the sound. The research results are published in Biology Letters.
By the sound of a voice, you can often judge a person's height. For example, tall people with a long vocal tract speak in a low voice with closer formants. Earlier research has shown that sighted people can gauge the height of a speaker by the sound of their voice and usually associate low pitch with tall stature. However, it is still unknown how people acquire this ability: with the help of training, that is, they periodically see how tall people speak in a low voice, or people, in principle, associate low sounds with large sizes, and then project this association onto the voice and body size … If the second is true, then the ability to compare low sound with large dimensions may be innate, or in order to compare sounds with dimensions one does not need to see an object, it is enough to hear it. To confirm or refute the second assumption, the authors of the work decided to test it on blind people.
The research involved volunteers aged 20 to 65 years. 68 men and women were blind from birth or completely blind during their lives, 23 people were sighted and constituted a control group. The authors of the article recorded vowel sounds that were pronounced by 30 adult men of different heights (the difference in height was from zero to 21 centimeters). The recordings were randomly paired and invited to listen to the participants in the experiment. They had to determine by the sound of the voice which of the speakers was higher. To ensure that all subjects were in equal conditions, sighted people were asked to close their eyes before the experiment.
It turned out that the number of correct answers was not affected by whether the participant was sighted or blind, as well as their gender and age. Correct answers accounted for approximately 56 percent of the total. The only factor that influenced the accuracy of the answers was the difference in the height of the men who spoke. The more significant the difference, the more accurately the participants responded. If the difference in the height of the speakers was maximum, 21 centimeters, the number of correct answers reached 89 percent.
According to the authors of the article, the results obtained indicate that the ability to match voice and height may be innate or in order to acquire it, a visual component is not needed.